Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Too hard for my engine, how about yours?

Author: Uri Blass

Date: 13:37:41 11/04/02

Go up one level in this thread


On November 04, 2002 at 16:24:56, Uri Blass wrote:

<snipped>
>>>>[D]2bq3k/2p4p/p2p4/7P/1nBPPQP1/r1p5/8/1K1R2R1 b - - 0 1 bm Be6, am c2;
>>>>Bagirov-Gufeld 1973
>>>
>>>This position is also member (13) of the BT2630 testsuite.
>>>
>>>1:26 for Be6 with Be6 Bxe6 Nd3 +47cp
>>>FH after 1:40 +105cp and 1:52 with +163cp
>>>finally after 5:07 531cp with the line
>>>1...Bb6 2.Qc1 c2+ 3.Kb2 Bxe4 4.Kxa3 c5 5.Kb2 Qb6 6.Kc3 cxd1Q 7.Qxd1 Nd5+
>>>8.Kxc4 Ne3+ 9.Kd3 Nxd1
>>
>>Very nice.
>>So, how is it done? ;)
>
>This seems to be hard for movei
>
>It likes c2+ very much and only at depth 9 starts to fail low from
>2.82 to 2.52 but at depth 10 the score goes up again to 2.53
>
>depth=10 +2.53 c3c2 b1b2 c2d1q g1d1 a3h3 d1f1 c8e6 f4h6 h3h2 b2b1 e6g8 d4d5 c7c5
>Nodes: 21271672 NPS: 144616
>Time: 00:02:27.09
>
>2:27.09 is the time to finish depth 10 on p850 and getting a score at depth 11
>takes a long time.
>
>Uri

Movei gets a big fail low at depth 11 so maybe it is only a question of time for
it to find it by search.

depth=11 +0.66 c3c2 b1b2 c2d1q g1d1 a3h3 d1f1 c8g4 h5h6 g4f5 e4f5 d8b8 f4d2 b4d5
b2a2
Nodes: 111104579 NPS: 143247
Time: 00:12:55.61

Note that I believe that movei can be at least 1.5 times faster without
assembler tricks by optimizing it.

Better search rules including better use of hash tables can also help it to find
the fail low faster.

Uri



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.